POS0262 HUMORAL AND CELLULAR SARS-CoV-2 VACCINE RESPONSES IN PATIENTS WITH GIANT CELL ARTERITIS AND POLYMYALGIA RHEUMATICA
Authors: Y. Van Sleen, K. Van der Geest, R. Reitsema, I. Esen, J. H. Terpstra, E. Raveling-Eelsing, M. Van der Heiden, J. Jansen, A. Buisman, D. Van Baarle, M. Sandovici, E. Brouwer
Journal: Annals of the Rheumatic Diseases (2022)

Background Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are overlapping autoinflammatory diseases affecting people over 50 years. The diseases are treated with immunosuppressive drugs such as prednisolone, methotrexate, leflunomide and tocilizumab. Even though GCA and PMR patients have a substantially higher risk for infections, little is known about humoral and cellular immune responses after vaccination in these patients. Objectives In this study we assessed the immunogenicity and safety of SARS-CoV-2 vaccinations in these diseases. Methods Patients (n=45 GCA, n=33 PMR) visited the outpatient clinic twice: pre-vaccination and 4 weeks post-vaccination (BNT162b2 or ChAdOx1 vaccine). Patients with previous SARS-CoV-2 infection were excluded. In both pre- and post-vaccination samples, anti-Spike antibody concentrations were assessed and compared to age-, sex- and vaccine-matched control groups (n=98). In addition, the frequency of SARS-CoV-2 Spike-specific T-cells was assessed by IFN-γ ELIspot assay, and side-effects and disease activity were recorded. Results The GCA/PMR patients, as a group, did not have reduced antibody concentrations compared to controls. However, linear regression analysis revealed a significant association of methotrexate and &gt;10mg/day prednisolone use with lower antibody concentrations in GCA/PMR patients. Evidence of cellular immunity, as assessed by ELIspot assay, was found in 67% of GCA/PMR patients, and was correlated with humoral immunity (Figure 1). Patients using &gt;10mg/day prednisolone had reduced cellular immunity. Importantly, vaccination did not lead to significant side-effects or changes in disease activity. Figure 1. Spot-forming cell (SFC) counts in the ELIspot assay. SFC counts, indicating IFNγ producing cells, increased significantly (Mann Whitney U) at post-vaccination compared to pre-vaccination. Red line indicates the median (A). SFC counts correlated with Spike antibody concentrations in GCA/PMR patients vaccinated with BNT162b2 (B). GCA/PMR patients using &gt;10 mg/day prednisolone are indicated in red. For the correlation, the specific SPC counts are used in the post-vaccination sample after subtracting the SPC count in the pre-vaccination sample. Statistical analysis by the Spearman correlation coefficient. BAU: binding antibody units Conclusion SARS-CoV-2 vaccination was safe for GCA/PMR patients and immunogenicity was comparable to other older individuals. However, patients using methotrexate and particularly &gt;10mg/day prednisolone did show lower vaccine responses, which corroborates findings in other autoinflammatory patient populations. These patients may therefore be at higher risk of (potentially even severe) breakthrough SARS-CoV-2 infection. Acknowledgements This study was supported by the Dutch Vasculitis Foundation (Vasculitis stichting). Disclosure of Interests None declared